clipped from arstechnica.com

Every once in a while, an article gets posted somewhere in the blogosphere about how Microsoft needs to release a complete Windows rewrite, something along the lines of what Apple did with Mac OS X. Most people realize that Microsoft is in no position to pull a stunt like that at the moment; it's hard to see Microsoft phasing out support for a billion-Windows-PC-strong user base, but that day may one day come, perhaps thanks to robust virtualization technology.

But in the meantime, Microsoft has settled on rewriting bits and parts of the Windows operating system as it sees fit, with Vista being one of the biggest rewrites (a fact which partially explains the many hardware and software compatibility issues XP's successor experienced at launch). Speculation around a non-Windows operating system in the works at Microsoft has been present for years, but recent trustworthy tidbits of information have found their way into the hands of Microsoft ZDNet bloggers Mary Jo Foley and Ed Bott.